Whip roll mechanism for looms



Dec. 26, 1950 J. E. REPASS 2,535,515

. WHIP ROLL MECHANISM FOR LOOMS Filed June 7, 1949 2 Sheets-Sheet 1 a 1 m 1 \12 35 I E 13 E5" l 6 ll 'llH T 1" i i "ii? 8 11} 10 5a 57 m '1 11 40 H 45 I Q a" 24 1.5 Q I 19 25 Q l\ )1; 2o v o- 12 7 H 22 l6 15 26 INVENTOR. 18 17 JAMES E. REpAss BY ATTORNEY Dec. 26, 1950 Filed June 7, 1949 J. E. REPASS WHIP ROLL MECHANISM FOR LOOMS 2 Sheets-Sheet 2 INVENTOR.

J4ME5 E. REPAss ATTORNEY Patented Dec. 26, 1950 This invention pertains to improiie'iiiefits" iri i/hicli' is" vvll ii'nd ""stoo'd" by those genvei safi moms; and moresp'ecifie'ail'lfi to iriiprei eifiefits in withtfii's' art, tljeii froifilthe whip roller to t biasing means'as appl "tothe whip 1 (if a? 160mof the type in' which the ware-tn let oiffrom a beam and'p'as'sed over whip'roll by which tension iri Sa-id'WaTHtHreaYiSi's" to govern thelet-ofime'chanisrnand't v v the rate at 'whichfit fiincti'oris to'p'eiifiit tee-Ware dr otfieriiiisedor'inecte t' threads to be drawn rrom-thebeam, H I asfiieriiiitte'ds'o td do under the; infliie'nce ofco It isa general object of the invention to devise 10 trol mechanism,- the regulation of which'iis iii'q an improved'mean's"by which awhifir'ollof mere f feiiiiently derived frointensiori injfiiience's or less conventional type' ma 'be"biasd and the" warp sheet; Since thejwarp'isheet 7 effect upon thewarb' sheet passingdverit" care" dver the whip roll these tension infl' i'ences re filllfir contiOledafidadjfisted; cdl'li eiiie fitly COIiVeYd thro'i'ig'fi the W It is a"morejs'p'eciiic"objectof'the'i ran njecfhanisinand certairifirit etni ee' in provide" a more o'r"1e'ss' urinary; Self agewme said'1et if The biasing? means 'inclutiifig springs enclosed" w a casing the parts'ofwhich erv'e'irra djustifg t 8 tension in the sbriiigsi' and in cofive'yingtthe l ernin'geifect T the 931E111 "fly 'IIlfifidi-Whip i bll tfi' the control mechanism fbr'the le if It isa further object of the'ii iventi'oii-to d whip. r011 biasing means which may employ are 1; type springs and to confine the In hai iisfh w in a're'atively smau'space sd'theitit cf s n" fiict with functioning of other parts of the loo'ri'i; nor will it stand in the way ofor'lirn'it' acc'ess V at" the we rearpartiafiof" the loorri'sides or e51; to the functional parts of the'looin or theme tensions thereof,- and: to which 'a're fined short accessibility of thewarp ,bearfi particularly t eaims-carrying; fre'lj rotatable roll, ifiiist'be introduction orremov'al of the beaifi fro'r'ri the biased or urged ina'dirction'such' thalfit'nof loom. h man vtends toei'geit aftensiohinginflfienceionthe It is a further object" tbd'eVlS' m'ChaIIfi'sm'Qf This biasing Ifi ifi/effiefifi iS" cdiig this type which shall decreaseand ractically vefi tS'iJe-"of sbring anif minimize the possibility'of injurfi to personnel lev echainisirfl those springs heretofore" em: in the event of spring breakage'or for: any other p'l'qye'd iii"mest'ifistanib hg"oftheiieiiai'df reason, e; g., during thefiialii'ng' of adjustments. do were and being methane an armor let er Furthermore, it isan object of'tlie invention to" a dto tl'i'ewhfiTrolLl bittitspiiitllthifi provide a spring or springs of the type'described' orto seme'cefivemefit part a: the whifiroll strucwhich shal be capable of being s'ubjecte'd'to rela I ture so as" to be" elongated (or eoiii'firess'ii) i'fr'f tively great tension forces, but which shall offer accordance with the details of design to be fauna no particular hazardto those eifecting adjustin' a'liyi particular installa't The othr erids ments or in the-vicinity of the loom sincethe of th ses'prings arefco'fiv'riientlj teacher to spring orspringsare"substantially enclosed ai cf siii'taifilefiied'elefffentsI V v the adjusting means isalways' in full engage helical springs are generally of con; ment. v v eiigtfiandinnstheattaohed in exffied Other objects oftheinvention will become a s "'t tH parent from the following more detailed descr j e tion of the invention and the manner in'which re (1y accessibility f otherfparts' at that norti d n it is employed.' V A oft loo'rfi A airi; iiithe'eteiii"thh 'tfi In looms of the general cha'i'eict'r Her gs br or becoins'"de't described; a; warp beamfis moiinte'diri hearingsor gudge'ons at he rear portion of the" l'doni" framework and' the warp threads} collectively? referred to as 'a warpslfeet; aredrawnthei'ef om and over a whip ran the general" function of In constant tension let-offs it is desirable that considerable adjustment be provided and therefore these springs previously employed have had to be connected to some part of the loom structure or some projection therefrom which may be moved throughout a considerable range for that purpose. That has likewise complicated the mechanism, has rendered it more costly than desired and also made it necessary for the loom operator, when effecting adjustments, to work in a position not conducive to comfort nor to effecting relatively fine adjustments of the parts.

The invention herein described and claimed is directed toward improvements in the resilient biasing means for such whip roll devices and briefly, comprises an application of a clock type or spiral spring or springs directly to or concentric with the pivot spindles on which the whip roll is adapted to swing, and which are 'also readily and easily adjustable for varying in a precise manner the tension to be applied by the whip roll to the warp sheet trained thereover. Springs applied at one side of the whip roll device are enclosed within a casing with the exception of one end of each spring which may project through an opening in the casing to be connected to anchor means for that end of the spring. One portion of the casing is adapted to convey the angular movement imparted by the tensioned warp sheet to the whip roll mechanism through connecting linkage of more or less conventional nature by which the warp beam advancing motion imparted through the left-off is carefully regulated. The other portion of the casing is preferably freely mounted on the whip roll pivot and is adjustably interconnected to the said pivot means for the whip roll through a peculiar type of worm and worm wheel device hereinafter to be described in greater detail. The adjustment effected by the above mentioned means is one conveniently made and also is effected without any possibility of injury in the event of the spring or springs breaking or other unforseen difficulties arising due to displacement of a spring or other releasing thereof as might sometimes occur with springs fully exposed and which have no guiding or restraining parts constantly associated therewith.

The let-off action as controlled by the whip roll under the influence of biasing means herein described and claimed is one found to be very effective when employed as a constant tension let-off not requiring any follower mechanism for compensating for differences in beam diameter, and is also capable of taking care of let-back of the warp up to a relatively great number of picks without noticeably disturbing the quality of ma terial being woven and without requiring any manual attention at the let-off portion of the loom.

The invention is hereinafter to be described by reference to one preferred embodiment thereof as evidencd in th attached figures of drawing wherein:

Fig. 1 is a side elevation of that portion of a loom to which the invention has been applied and includes enough of the loom parts which cooperate with the whip roll and are controlled thereby to show the mode of operation thereof.

Fig. 2 is a plan view of, that side of the loom illustrated in Fig. 1 and further illustrating the parts shown therein.

Fig. 3 is a detail view taken from the end of the whip roll ivot shaft or spindle and having a part of the spring enclosing means broken away.

Fig. 4 is a partial section taken vertically along the center line of Fig. 3 and further showing details of the mechanism.

Fig. 5 is a detail view in which certain of the parts incidental to efiecting adjustment are more fully illustrated.

Fig. 6 is a fragmentary view showing the anchoring means for the outer spring ends.

Now referring to Figs. 1. and 2, the rear left hand portion of a loom is shown and comprises loomside I0, extension II, a warp beam generally indicated by numeral l2 and having a gear 13 with which meshes a pinion l3 which forms the terminal drive element of a let-off generally indicated by numeral l4 and, as herein shown, of Bartlett type, although it is to be understood that the invention is not at all dependent upon the type of let-off employed, but may be used with any let-off controlled by tension of the warp sheet as it aifects the position of a whip roll or similar mechanism.

The let-off is ratcheted by pawls l5 and [6 which make engagement with the teeth of a ratchet wheel I! thereby to drive shaft l8, worm l9, gear 20, etc. Motion for this let-01f ratcheting means is derived from the lay structure of the loom, or may be taken from a crank or other operative part thereof, and includes a driving rod 2 I, a connecting rod 22 attached at one end to a spider 23 rotatable on shaft l8 and which has mounted thereon the spring pressed pawls l5 and iii. The amount of movement which is permitted the pawls themselves is controlled by a lever 24 pivoted at 25 and having its lower, forked end 26 engageable about the connecting rod 22 between collars 21 and 28, adjustably secured to the rod by set screws. Depending upon the angular position of the lever 24, the active or eifective movement of rod 22 is governed to impart to the ratchet wheel any desired movement from one by which a relatively great number of teeth are affected to a condition in which no ratcheting movement at all is imparted. It is this lever 24 which is directly acted upon by the angularly movable whip roll in a manner as will hereinafter be described.

The warp threads are drawn from the beam !2 and pass upwardly about the freely rotatable whip roll itself which is designated by numeral 29. This whip roll is carricd at the outer or free ends of a pair of arms 33, it being understood that the structure at the opposite side of the loom (not shown) is substantially the same, except for the fact that there need be no let-off mechanism at that side and therefore the control for the let-off is taken at this left hand side of the loom as herein described, although it is quite evident that the let-off, if at the opposite side of the loom, would be controlled from the unit adjacent thereto.

These arms 38 have hub portions 3! from which extend and within which are fixed the shafts or spindles 52, one at either end of the machine, and which are freely pivotcd in bearings 33 so that the whip roll 29 under the influence of the tensioned warp sheet may move angularly about an axis defined by these spindies 32.

As herein illustrated, the warp sheet, after passing about the whip roll 29, is trained around a drag roll 34 clamped between members 35 and 36 and held in a properly disposed position after adjustment which may be effected through swinging the drag roll about a pivot point at which it is locked and maintained in a definite. position by the serrations or. teeth, 31?, onaset of which is formed; in thelower clamp,-v ing. memben 35., the. th;r or complementary teeth being-formedas a part of a collar 33 at the outer, upper. end of. the loom-side extension II.

This to-be-understood that this drag roll mayor may not. be used and that the actual construction thereof is ,not important,several types beingayailable, it alsoibeing well knownv that the actual threading or manner of passing the warp sheet aboutthewhiproll and drag roll is also capable of being varied in accordance with the.

particular design of. the parts and other ooniderations.

It: is to beunderstood that in certain instances a. single. unit only, may be employed at that side. of. thee-machine; atwhich the. control for the letoff, itself, is taken. Howevenit, is preferred that,

more or lessidentioal units be employed at each side, of the machine, that is, at each spindle 32 uponwhichthe whip roll is pivoted, since in that way the balance of the parts is more precisely regulated. While there may be some differences inthe units, they are preferably substantially the same and a description of one as hereinafter 1 01113 upwardly against the pull of the warpsheet in a manner understood by those conversant with this art. While two springs are housed within each casing as herein shown, and according to a preferred form which the invention may take, asingle spring or a greater plurality may be used depending upon circumstances. It is preferred that two springs be employed since;

each spring may be of less strength and, therefore-more easily handled and assembled and, in the event of spring breakage, all tension at one side of the whip roll is-not lost.

The casing-member has integrally-or otherwise formed as a part thereof a depending arm 42 which serves to impart the angular movements of the whip roll mechanism through a.- link 43-tothe lever 24, Fig. l, the function ofwhich was mentioned above. This depending arm 42 has a slot or elongated opening i t-within which is, slidably retained a stud or pin 45 extending from or threaded into a collar 46 which is adjustable along the length of the link or rod 43 and-fixed in position thereon by means of a,

In actual operation the-whiprollmay vibrate as is common in such devices due to.

set screw. 4 1.

the effect of the harness motion and to the be;atup, but that has no primary effect uponthe take-up control as it is only by abnormal posi tioning andupon greater angular movements of.

the whip roll about its pivot 32 and correspondirggmovement of thecasing lt and its depending arm. 42: that the link is actually pushed to,

the; right F'igs. l and 3, to permit engagement of;a.greater.nurnber of teethinthe ratchet wheel, i7, orelseis permitted to move in the opposite direction thereby toprevent a full number, or; perhaps-any, teeth being. engaged, all in a.-man ner-commomy understood by those; familiar. with,

let-o fs o the; type h re n. shownhe slotdt e mits: nsiderable movement.- of; he: whip, roll.- and of the a m; 4 without. any immediate change: imposition of the link, 43 r lever. 24., toasuch: as occurs when the fabric is let; lo.acl :,f that, sometimes bein necessary-in repairman-(ima filling; and such, movement may. be carried o; the-extent of five or morepicks without lossof. tension: andwithout it being necessary to; effect. any manual adiustments attheilet-ofi. In other; words, the list-7011f ascontrolledby the;.whip.ro1ll biasing. means f this case takes care oilettin back the fabric; throughout almost any extent which may normall bereqnired withoutattem tion upon the, part, of: the loom. operato 1:.

The enclosureof. thelsprings 4 l; is completed by; asecond casing'member 48 which. is. comprised; as a. disk or; plate having; ahub 4.5. slotted. or. grooved at four positions, more orless, these? grooves indicated. by numeral; 59, being de p enough and so, shaped as to receive the bent. or; curved; end 5! of, the spring 41... The spring-end; 5],. may be hooked into an appropriate one; of the: slots. or grooves, 50 and thenwhen, theouten end.- 52. of that spring isattachsd atan anchor 531 and; the casing member 48 rotatedin acountercloeke wisedirection, Fig. 3, the coils of the springwillbe tightened thereby tensioning it as is,nec essary for biasing the whip roll; 2-51 againstthe pull ofthe warpsheet with whatever degree of force is appropriate under thecircumstances.

Thehub 49 of he e d a n membermis freely rotatable upon. a sleeve54 which projects. along the spindle 32 asit extendsfrom ahub 55- which also hasextending. therefrom an arm. 55.

The; hub is maintained-in axial position on the, sleeve54 sinceit engages against a: shoulder tere minating the hub 55 at oneendand by aspr-ing; fastening 51', or by any other convenient retaining; means at the opposite end.

The anchor.v 5.3;is an integral partof a bracket 58, Figs. 3 and6, the latter beingbolted or other-- wise more or less. permanently attached to the, extension H at the rear portion of loomside UL. Inactual practice it is convenient to mount thebracket58 and anchor 53on' or aboutadowelor. pivotinot shown) andtoallow enough play at the boltholesfor the attachingmeanssothat. the, anchor may be, aligned with the outer ends of; the springs, 4| as they extend through an opening atthatparticular part of the casing member; 43. all as illustrated at Fig. 3. That permits-the springs to bear against the anchor; member with? out subjectingthem to any unnecessary-bendingor imposing thereon unnecessary strain.

For adjustably fixing the position of. the second, mentioned casing'member 481and therewitlnthe inner. hookedend 5| of the springs 4t, the arm '55 is; interconnected to the disk portion. of the.

casing memberand the hub 55,fixed-tothe;spindle; 32. The latter connection may. be elfectedby a key or by set screwssuch as those indicated here at 59, Figs. 4 and 5. The means for; lIltGlCOIlIlflCtr ingthe arm56 andthedisk portion of the-casing member 48 and for permitting adjustment bee tweenthe two comprises a, worm 5!]; which engages withintoothlike elements fil cast-or other-- wise ,formed in the; adjacent surface of-the casing member48. Acording to asimple and preferred embodiment which this partof the invention takesthese indentationsor toothlike depressions are; radially disposed and the-worm 60 merely comprises a: single thread or-turn-whichextends at a proper angle toengage the teeth Glinthe: disksincethelarm 56 isslig-htly curyedorother.

wise offset as illustrated in Fig. so that the angle made by the helix of the worm substantially approximates the angle then made by that toothlike depression 6| within which the worm convolution is meshed.

The hub of worm 6D is fixed as by means of a key 62, or in any other satisfactory manner, and is compelled to rotate with a bolt 63 or other spindle means which extends through bearings in the forked ends 64 and 65 of the arm head 66 of the bolt 63 permits the worm to be turned therewith by a suitable wrench or other convenient means and the nut 61 appied to the threaded end of the bolt is used to lock the parts in an adjusted position. Other equivalent constructions may be used at this point, but that herein described has been found to be effective and comprises a relatively inexpensive construction entirely adequate for its intended purpose.

The worm 66 and the toothlike identations 6i may, if cesired, be machined for greater accuracy or better conditions of interengagement, but in actual practice it has been found that cast parts serve quite well and therefore the cost may be reduced to a minimum by employing parts formed in that manner. A single threaded worm is effective, but double or other types of thread may be used if it is desired to speed up the rate at which an adjustment may be effected. In actual practice, adjustment is not frequently made except at the assembly of the mechanism and thereafter at rare intervals, and thus a socket or other wrench may be applied to the bolt head 68 and tightening of the spring or releasing of a slight amount of tension therein is efiected without consuming very much t.me since it is never necessary to rotate the casing member 48 relatively to the arm 5% more than a few degrees. Adjustment is easily effected while the loom is running.

Some variations in the actual details of construction are contemplated, but it is preferred that there be a plural number of springs in each casing thereby to use smaller springs and to facilitate assembly since heavier springs naturally are somewhat harder to handle. The whip roll, either one having separate pivot spindles such as that herein illustrated, or one having a shaft extending completely across the loom as is sometimes the case, should preferably have one of the biasing units at each end. One of these units may be provided with an arm such as the arm 42 by which linkage extending to the let-ofimechanism is controlled. The actual means by which the worm is rotated may vary, for example, it is not essential that the bolt be of a type having a hexagonal head and nut and, in

fact, various interconnecting means may be devised to which a wrench or crank or like instrumentality may be applied for effecting the adjustment by turning the worm on its axis thereby to rotate the disk and to tension or relax the spring or springs.

In actual operation it is to be assumed that the various adjustments have been effected so that the whip roll is biased against the warp sheet with the requisite amount of pressure for ordinary operating conditions. In most instances the collars 2i and 28, Fig. 1, are so adjusted and locked on the rod 22 that there is merely a working clearance between their inner surfaces and the adjacent portions of the forked end 2 .5 of the lower part of lever 24. The collar 28' should be positioned in that manner although it is not quite so essential that collar 21 be closely positioned since the device will operate with that collar spaced away from the end 26 of the lever, if desired. The normal operation of the loom merely causes the whip roll to assume a more or less neutral or running position in which it is effective for maintaining the casing member 40 against the tension of the clock type springs so that arm 42 maintains the link 43 and lever 24 in a position such that the pawls l5 and 18 engage the ratchet teeth on the wheel l1 and rotate the take-up mechanism throughout a slight extent for every beat of the lay or in synchronism with the weaving cycle. This actual rotation may vary from pick to pick, but the sum total of the ratcheting movements will be effective over a period of time to rotate the beam at a rate just fast enough to let off a sufficient length of warp threads as required in the weaving of the particular fabric being produced.

For weaving some fabrics, the forward movements of the link 22 move lever 2 through the collar 28, and thus link 43 in a direction to press the whip roll upwardly against the warp sheet every time the lay beats up. That assures that the fabric produced is tightly woven since each pick of filling will be beaten into a tightly held warp, and by suitable adjustment, this action may be varied as desired.

Whenever it is desired to let back fabric, the whip roll is permitted to rise since the warp is slaclrtened an amount corresponding to the number of picks let back, and the slot 44 in the arm 5?. permits angular displacement of the whip roll mechanism and of the casing members 42 without corresponding movement on the part of the link 43, lever 24, etc. The slot makes it possible for the whip roll under the influence of the springs 4| to maintain sufficient tension in the warp without any further let-off motion until the warp has been taken up after resumption of weaving and the whip roll is again drawn down to its normal running position.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

I claim:

1. For a loom of the type having a warp beam,

a let-off mechanism and a wh p roll through which changes in tension of the warp threads drawn from said beam and pa sing over the whip roll aifect said let-off to control the unwinding of the thread from the beam, an improved whip roll biasing means comprising a clock type spring, a casing means substantially enclosing said spring, means forming a part of one casing member to which one end of the spring is attached, an anchor for the other end of said spring, and an adjusting means effective for altering the relative position of said casing member to which the spring is connected thereby to adjust the tension therein and thus, its biasing effect upon the whip roll.

2. For a loom of the type having a warp beam, a let-off mechanism and a whip roll through which changes in tension of the warp threads drawn from said beam and passing over the whip roll affect said let-off to control the unwinding of the thread from the beam, an improved whip roll biasing means comprising a clock type spring, a casing means substantially enclosing said spring,

aaseamrt means Iorming a part :of one casing member to which one end Of the spring is attached, an anchor for the other end of said spring, and an adjusting means effective for altering the relative position *of said casing member to which the spring is connectedwhich comprises an arm fixed for swinging movement with said whip roll, a worm member carried by said arm and means by which said worm member may be rotated and held in a set position, and cooperating toothlike elements formed in said casing member and being complementary to said worm member and engaged thereby, said worm member being effective when rotated to adjust the position of the casing member angularly with respect to the said arm and whip roll thereby to tension the spring and to alter its biasing effect upon the whip roll.

3. For a loom of the type having a warp beam, a let-01f mechanism and a whip roll through which changes in tension of the warp threads drawn from said beam and passing over the whip roll affect said let-off to control the unwinding of the thread from the beam by said letofi, an improved whip roll biasing means comprising a clock type spring, a casing means substantially enclosing said spring, one part of said casing means having a hub portion to which the inner end of said spring is connected, the other portion of said casing being fixed to the whip roll pivot member and having means projecting therefrom to which may be connected a link for conveying movement of the whip roll to the said let-off, an adjusting means effective for altering the relative position of said casing member to which the spring is connected thereby to adiust the tension in the spring and to alter its biasing effect upon the whip roll, said means comprising an arm fixed for angular movement with the whip roll, a worm member carried by said arm and means by which said worm member may be rotated and held in a set position, and complementary toothlike indentations in that casing member to which the inner end of the spring is attached, said indentations being positioned for interen agement with the said worm member.

4. For a loom of the type having a warp beam, a l t-off mechanism and a whip roll through which changes in tension of the warp threads drawn from said beam and passing over the whip roll afiect said let-off to control the unwinding of the thread from the beam by said let-01f. an improved whip roll biasing means compris ng a clo k type spring, a disklike member freel rotatable on said whip roll pivot, said disk-like m m er having m ans forming a part thereof to which the inner end of said s ring is attached, an anchor for the outer end of said spring, and means for adjusting the ten ion in said spring by rotating the said disklike member about its pivot which comprises a plurality of toothl ke indentations in said disk, an arm fixed to said whip roll pivot and a worm m mber rotatably carried by said arm, means b which said worm member may be rotated and locked in a set position said worm member being positioned for interengagement in said toothlike indentations in the disk member to which the inner end of the spring is attached.

5. For a loom of the type having a warp beam, a let-off mechanism and a whip roll through which changes in ten ion of the warp threa s drawn from said beam and passin over the whip roll affect the let-ofi to control the unwinding of the thread from the beam by said let-off. an improved biasing means comprising a unitary 10 and selfcontained structure mounted upon the pivot means upon which the said whip roll is iangu'larly movable, said 'structurecomprising a clock type-spring, a casing formed of two parts, one said casing part being rotatably mounted upon the said whip roll pivot meansand the other said casing part being fixed to said pivot means and having an arm projecting therefrom to which is attached link means for imparting the angular movement of the whip roll to the said (let-off means, a :hub portion extending inwardly ef the casing from the first mentioned part thereof .an'd'to which theinner end of said spring is connected, an anchor means for the outer end of said spring, and means for adiustably tensioning said spring which comprises an arm :fixedly attached to'the said whip roll pivot means "and a worm rotatably mounted at the free end of said arm, a plurality of toothlike indentations in the said casing member to which the end of the spring is attached and within which said worm is operatively engaged.

6. For a loom of the type having a warp beam, a let-off mechanism and a whip roll through which changes in tension of the warp threads drawn from said beam and passin over the whip roll affect said let-01f to control the unwinding of the thread from the beam, an improved whip roll biasing means comprising a clock type spring, a casing means for said spring, and means forming a part of said casing to which one end of the spring is attached, an anchor for the other end of said spring, and an adjusting means effective for altering the relative position of said casing with respect to the said anchor, thereby to ad ust the tension in the spring and its biasing effect upon the whip roll.

7. For a loom of the type having a warp beam, a let-ofi mechanism and a whip roll through which changes in tension of the warp threads drawn from said beam and passing over the whip roll affect said let-off to control the unwinding of thread from the beam, im roved whip roll biasing means comprising a clock type spring, one at each end of said whip roll pivot means, a casing for each clock type spring, and means forming a part of each casing to which one end of the spring is attached, anchors, one for each s ring, to which that end of the s ring opposite the end connected to the casing is attached, an adiusting means effective upon each of the casings for altering the relative position of the casing to hich the spring is connected thereby to ad ust the tension in the spring and its biasing effect upon the whip roll.

8. For a loom of the type having a warp beam, a l t-off mechanism and a whip roll the ends of which are retained in crank means swingable upon pivot s indles fixed in said crank means, said whip roll comprising a means through which changes in tension of the warp threads drawn from said b am and pa sing over the whip roll affect said let-off to control the unwinding of thread from the beam, improved whip roll biasing means at each end of said whip roll and connected for functioning upon the spindles upon which the whip roll is pivoted, said means comprising a clock type spring, casin means for each spring, means forming a part of each casing to which one end of the spring individual thereto is attached, anchor means for the other ends of each of said springs and an adjusting means e-fiective upon each casing for altering the relative position thereof for adjusting the ll tension in the spring and thus, its biasing eifect upon the whip roll.

9. Improved whip roll biasing means for looms of the type described which comprises a clock type spring, a two part casing means substantially enclosin said spring, inwardly projecting means forming a part of one casing member to which one end of the spring is attached, an anchor externally of the casing for the other end of said spring and an adjusting means effective for altering the relative position of said casing member to which the spring is connected which comprises an arm fixed for swinging movement with said whip roll, a worm carried by said arm and means by which said worm member may be rotated and held in a set position, and cooperating toothlike elements formed in said casing member to which the said spring 12 is attached, said elements being complementary to said worm and engaged thereby; said worm being effective when rotated to adjust the position of the casing member angularly with respect to the said whip roll thereby to tension the spring and to alter its biasing effect on the whip roll.

JAMES E. REPASS.

REFERENCES CITED The following references are of'record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,273,460 Brown Feb. 17, 1942 2,501,157 Brown et al. Mar. 21, 1950 

